Bad Arguments to Add Items to List

[Curly Girlz]

Currently trying to finish up a log-in/ register screen for an app. The user registers. Usernames and passwords are stored in a list and the items in the list are then stored in a TinyDB so that when the user re-enters the app they can sign-in with the same username and password they registered with. After clicking register (which prompts app to add usernames/passwords to lists and stores them in Tiny DB), I get an error saying "The operation add items to list cannot accept the arguments: [*empty string*],[bees]" (bees was the username input).  I thought I could fix the problem by verifying that values in the TinyDB are not empty strings, but I see no way to do this. Are there any fix(es) for this problem?

[Nico Marikucza]

There is something wrong with your blocks, see annexes.

Nico

[Abraham Getzler]

You are using global variable logUser in two different ways:

In one place you treat it like a single user name

In another place you treat it like a list of all the user names.

Likewise with the password(s).

Spend a byte or two, they're cheap.

See HOW TO WORK WITH LISTS in this FAQ

https://groups.google.com/forum/?utm_medium=email&utm_source=footer#!msg/mitappinventortest/2cd6Uz__xA0/cPQSiZpcDAAJ

Also, make some more global variables, with names reflecting their function, like

NameToPasswordMap, a two column table with name in column 1 and password in column 2,

for use with the list block LOOKUP IN PAIRS.

Also, if you keep a list in TinyDB, never use blank as a default

if not found.  Use CREATE EMPTY LIST instead as a default.

ABG